496 Miseellaneouf Intelligence, 



tinued. They relate — 1. To the fecundation of the plant naturally 

 or artificially, by its proper pollen: 2. To fecundation by the pollen 

 of another plant: 3. To the action of pulverulent substances; as 

 sublimed sulphur, pulverised charcoal, carbonate of mafrnesia, lyco- 

 podium, &cr. and 4. To the duration and mode of action of the 

 pollen of one plant upon the ovaria of auotlier; principally to ascer- 

 tain whether any influence would be exerted upon the form, colour, 

 or time of maturity of fruits and seeds. 



The followinj^ are a few of the facts ascertained. A microscopic 

 quantity of the pollen proper to a plant bein^ placed upon its pistil, 

 has so g-reat an influence as entirely to destroy the action of a larc^e 

 mass of the pollen of another plant, even though of a very near 

 species: the proper pollen of a plant being applied by means of a 

 pencil to the stigma, becomes so exactly attached to it, that it is 

 '<lifficult to remove it without injuring the stigma : with the pollen 

 of another plant it is quite otherwise ; the stigma then appropriates 

 it with difficulty and slowly, and the difficulty increases with the 

 difference between the species. When the fecundation of one 

 plant is occasioned by the pollen of another, the pollen applied 

 to the stigma disappears in a time which, all other circumstances 

 remaining the same, varies as the affinity between the species is 

 more or less. When once the pistil is saturated with fecundating 

 matter, that which is afterwards applied undergoes no change 

 either of form or colour. In natural fecundation, the stigma loses 

 its fullness and freshness as soon as it is saturated with fecun- 

 dating matter ; in the cross fecundation, the stigma remains un- 

 changed for a much longer time, and even sometimes seems to be 

 renewed in vigour. In the latter case, the pollen which is re- 

 applied disappears until the stigma loses its freshness. The foreign 

 pollen retards rather than accelerates fecundation. 



M. Gaertner has extended his observations much further, even to 

 observing the changes in the corolla; on the secretion of the juices 

 of the plant; on the period of ripening; on the different states of the 

 seeds, &c. &c. — Bui. Univ. B. x. 77. 



12. On a natural Botanical Arrangement dependant on Chemical 

 Characters. — Many naturalists have endeavoured to establish an 

 analogy between the external forms of plants and their medicinal 

 characters. Dr. Runge has undertaken to prove by analysis, that, 

 there is a chemical relation — 1. Between the different parts of 

 a plant (species) ; 2. Between the different species of a genus ; 

 3. Between the different genera of a family. To the first point, he 

 quotes the experiments of Vauquelin on the Hippocastan, and 

 his own upon Belladonna and the oak; from which it results, that 

 tannin is found in every part of the first and third, even* to the 

 cotyledons of the latter, and the narcotic principle in every part of 

 the second. Relative to the second point, he observes that prussic 

 •acid has been found in the kernels of all the species belonging to 



